Nitrous oxide makes up an extremely small amount of the atmosphere - it is less than one-thousandth as abundant as carbon dioxide. However, it is 200 to 300 times more effective in trapping heat than carbon dioxide.
Nitrogen is removed from the atmosphere by plants and converted into forms such as ammonia, which can then be used by the plants. This is called nitrogen fixation. At the same time, micro-organisms remove nitrogen from the soil and put it back into the atmosphere - denitrification - and this process produces nitrous oxide. Nitrous oxide also enters the atmosphere from the ocean.
Nitrous oxide has one of the longest atmosphere lifetimes of the greenhouse
gases, lasting for up to 150 years.
fossil fuels and wood is one source of the increase in atmospheric nitrous
oxide, however the main contributor is believed to be the widespread use
of nitrogen-base fertilisers. Sewage treatment plants may also be a major
source of this gas.
Since the Industrial Revolution, the level of nitrous oxide in the atmosphere has increased by 16%.
Due to the long time it spends in the atmosphere, the nitrous oxide that
we release today will still be trapping heat well into the next century.